Sorry, I don't have any pictures, but I know where there are some.

I got the idea from MadMax on the Thirdgen.org board and there are some photos there of the mods he did to his and I believe some other photos of mods done by other guys.

I went even farther than MadMax did since I'm running more cubes and was not as concerned with the potential of low end torque loss. In fact, I feel I gained low end torque instead of losing any.

Here's my thinking: The TPI setup was designed by GM for a 305 engine and the 305's breathing requirements. Then the system was put on a 350, an engine that is 45 cubes bigger, and larger injectors installed along with the required computer programming.

Result was a great low and mid range torque combo.

So here comes Jake and bolts that same setup on a 415, now 110 cubes bigger than the orginal design application. Needless to say, airflow was hampered a lot.

What I did, after reading MadMax's posts and looking at his pics, was to get an electric Mikita high speed grinder and some carbide bits and begin grinding away.

I began with stock plenum, BBK siamesed aftermarket runners and a stock base manifold.

I took out the dividing walls that are between the ports on the plenum, runners (both ends) and the intake manifold. I ground back the dividng walls as far as I could reach with the grinder, which ended up being three or four inches. When I finished, the ports resembled a horizonal "V" shape.

The plenum and base manifold ended up looking like those photos you see of someone looking through binoculars (like a hourglass laying on it's side).

I used sanding rolls to smooth everything out after I'd gotten the basic shape and the amount of metal removed that I was shooting for.

I used the same grinding bits to open up the stock type runner gaskets to match the now much larger port openings. I bolted the gaskets to the plenum, then ground the gasket material until it matched the opening. I then did the same thing with the runner to manifold openings.

A thin swipe of 02 safe silicone sealant on the gaskets prevent any leaks; none of the gaskets have leaked and it's been quite a while now.

One guy who posts on Thirdgen even cut his runners apart to remove the entire dividing wall, then welded them back together. I didn't go this far because I don't have welding skills.

I posted the exact measurements on the Thirdgen.org site last year right after I completed the mods. You can search their archives for the exact measurements I posted.

Hope this helps and let me know if I can help further.

BTW, I see you live in my home town. Lived there all my life until retired and moved to TX in 1995.

Jake


[Modified by JAKE, 4:07 PM 1/5/2002]

 

I did some checking for you and the title of the thread is "For those who dont read tech central(Right) Anti-tuning, a cut+paste".

The last post on the topic was 28 Dec 01.

There are some photos posted on that thread too.

Jake